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CVE-2026-23986
Vulnerability in copier (CVE-2026-23986)
Summary
vulnerability in copier (CVE-2026-23986). Data can be tampered with by attackers. Exploitable via ``os.scandir``. Mitigation: upgrade to `9.11.2` or later.
AI summary snake-internal / snake-material-v2
A vulnerability tracked as **CVE-2026-23986** has been found in copier.
Attackers can target a specific entry point like ``os.scandir`` over the network to misuse the product.
Data can be tampered with by attackers. CVSS score: ?/10.
What to do: upgrade copier to **9.11.2** or later.
If unsure, ask your IT team or search "copier CVE-2026-23986" on the vendor's site.
CVE-2026-23986 (copier) — CWE-61 /
Attack vector: local / unauthenticated
Attack surface: `os.scandir`
Patched: `9.11.2` — apply immediately
Plan: 1) Audit SBOM/dependencies, 2) Stage→prod upgrade, 3) Add WAF/proxy monitoring on affected endpoints, 4) Hunt IOCs in logs.
Refs: see the GHSA / vendor advisory / patched release linked on this page.
❓ What is the problem
**A vulnerability** (CWE-61) exists in copier. Attackers reach the vulnerable code path via ``os.scandir`` without authentication.
📍 Affected scope
copier — . Attack surface: `os.scandir`.
🔥 Severity
Severity: ?. Data can be tampered with by attackers
🔧 How to fix
Update to **9.11.2**.
🛡️ Workaround
Until the patch is applied: disable the affected feature, apply WAF rules, or restrict access via network ACLs.
🔍 Detection
Search webserver/proxy logs for unusual request patterns matching this CVE's known IOCs. Run `grep -r 'copier' .` against your dependency files (package-lock.json, requirements.txt, go.sum) to find affected services.
Response Actions (7 steps)
Concrete steps and command examples for SOC/SRE teams to execute in order
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1Identify exposure identify
grep -r 'copier' . | grep -v node_modulesリポジトリと本番環境の依存ファイル (package-lock.json / requirements.txt / go.sum / Gemfile.lock 等) で `copier` を grep し、稼働しているサービス・バージョンを把握する。
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6Apply patch patch
Upgrade copier to 9.11.2ステージング環境で 9.11.2 に上げて回帰テスト → 本番反映。回帰テストはアプリの主要ハッピーパスと、Step 3 で見つけた異常検知の続報チェックを含めること。
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7Post-deployment verification verify
Confirm patched version is live in productionパッチ適用後、ステージングで PoC または同等の悪用パターンを再現して脆弱性が閉じたことを確認。本番では Step 3 と同じログクエリでアラート再発が無いか継続監視。
Affected packages
PyPI
copier
[{"type":"ECOSYSTEM","events":[{"introduced":"0"},{"fixed":"9.11.2"}]}]
References
- advisory https://nvd.nist.gov/vuln/detail/CVE-2026-23986
- advisory https://github.com/advisories/GHSA-4fqp-r85r-hxqh
- package https://github.com/copier-org/copier
- package https://pypi.org/project/copier
- web https://github.com/copier-org/copier/security/advisories/GHSA-4fqp-r85r-hxqh
- web https://github.com/copier-org/copier/commit/b3a7b3772d17cf0e7a4481978188c9f536c8d8f6
- web https://github.com/copier-org/copier/releases/tag/v9.11.2